Electromagnetic interference shielding apparatus and methods of making the same

ABSTRACT

According to various aspects of the present disclosure, exemplary embodiments are provided of shielding apparatus that are suitable for use in providing electromagnetic interference shielding for one or more electrical components on a substrate. The shielding apparatus may have partially drawn and partially formed corner sections for improved rigidity. In one exemplary embodiment, a shielding apparatus generally includes side walls configured to be disposed generally about one or more electrical components on a substrate. Corner sections are integrally formed with the side walls. Each corner section has a drawn portion integrally connecting a corresponding pair of side walls, and a lower portion located generally below the drawn portion and generally between side edge portions of the corresponding pair of side walls.

FIELD

The present disclosure relates generally to shielding apparatus forelectronic systems and devices, and more particularly to shieldingapparatus that may have partially drawn and partially formed cornersections for improved rigidity.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Electronic equipment often generates electromagnetic signals in oneportion of the electronic equipment which may radiate to and interferewith another portion of the electronic equipment. This electromagneticinterference (EMI) can cause degradation or complete loss of importantsignals, thereby rendering the electronic equipment inefficient orinoperable. To reduce the adverse effects of EMI, electricallyconducting (and sometimes magnetically conducting) material isinterposed between the two portions of the electronic circuitry forabsorbing and/or reflecting EMI energy. This shielding may take the formof a wall or a complete enclosure and may be placed around the portionof the electronic circuit generating the electromagnetic signal and/ormay be placed around the portion of the electronic circuit which issusceptible to the electromagnetic signal. For example, electroniccircuits or components of a printed circuit board (PCB) are oftenenclosed with shields to localize EMI within its source, and to insulateother devices proximal to the EMI source.

As used herein, the term “EMI” should be considered to generally includeand refer to both EMI and RFI emissions, and the term “electromagnetic”should be considered to generally include and refer to bothelectromagnetic and radio frequency from external sources and internalsources. Accordingly, the term shielding (as used herein) generallyincludes and refers to both EMI shielding and RFI shielding, forexample, to prevent (or at least reduce) ingress and egress of EMI andRFI relative to a housing or other enclosure in which electronicequipment is disposed.

SUMMARY

According to various aspects of the present disclosure, exemplaryembodiments are provided of shielding apparatus that are suitable foruse in providing electromagnetic interference shielding for one or moreelectrical components on a substrate. The shielding apparatus may havepartially drawn and partially formed corner sections for improvedrigidity. In one exemplary embodiment, a shielding apparatus generallyincludes side walls configured to be disposed generally about one ormore electrical components on a substrate. Corner sections areintegrally formed with the side walls. Each corner section has a drawnportion integrally connecting a corresponding pair of side walls, and alower portion located generally below the drawn portion and generallybetween side edge portions of the corresponding pair of side walls.

In another exemplary embodiment, a shielding apparatus generallyincludes an upper surface and side walls integrally formed with anddownwardly depending from the upper surface. The side walls areconfigured to be disposed generally about one or more electricalcomponents on a substrate. The side walls have side edges that are eachconfigured for interlocking engagement with a side edge of acorresponding adjacent side wall. Corner sections are integrally formedwith the side walls and the upper surface. Each corner section includesa drawn portion integrally connecting a corresponding pair of side wallsand the upper surface. The drawn portion downwardly depends relative tothe upper surface. Each corner section also includes a lower portionlocated generally below the drawn portion. The lower portions includesseams formed by the interlocking engagement of the side edges of thecorresponding pair of side walls. For each corner section, there is alsoan opening located cooperatively defined by the drawn portion and thelower portion of the corner section.

Other aspects relate to methods of making electromagnetic interferenceshielding apparatus having side walls and a corner section generallybetween each corresponding pair of side walls. In one exemplaryembodiment, a method generally includes drawing a piece of material toform a drawn portion for each corner section that integrally connects acorresponding pair of side walls. This particular method also includesforming the piece of material such that the side walls are configured tobe disposed generally about one or more electrical components on asubstrate, and such that each corner section includes a lower portionlocated generally below the drawn portion and generally between sideedge portions of the corresponding pair of side walls.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is an exploded perspective of an exemplary embodimentillustrating a shielding apparatus together with a printed circuit boardto which the shielding apparatus may be secured;

FIG. 2 is a perspective of the frame of the shielding apparatus shown inFIG. 1 with the frame inverted;

FIG. 3 is a partial perspective of a side wall of the frame shown inFIG. 2 and illustrating castellations formed along a lower edge portionof the side wall;

FIG. 4 is a partial perspective of the frame shown in FIG. 2illustrating (the exterior of) a corner section of the frame in whichside edge portions of adjacent side walls interconnect to form a lowerportion of the corner section;

FIG. 5 is a partial perspective illustrating a corner section frominside the frame shown in FIG. 1;

FIG. 6 is a partial perspective of another exemplary embodiment of aframe of a shielding apparatus with the frame inverted to betterillustrate (the exterior on a corner section of the frame formed byanother interconnection of side edge portions of adjacent side walls;

FIG. 7 is a perspective of another exemplary embodiment of a frame of ashielding apparatus;

FIG. 8 is a partial perspective of the frame shown in FIG. 7 andillustrating (the exterior of) a corner section having a generallysquare-shaped lower portion formed by another interconnection of sideedge portions of adjacent side walls;

FIG. 9 is a partial perspective of another exemplary embodiment of aframe of a shielding apparatus where the frame includes corner sectionseach with a generally square-shaped lower portion formed by stillanother interconnection of side edge portions of adjacent side walls;

FIG. 10 is a perspective of another exemplary embodiment of a frame of ashielding apparatus in which corner sections of the frame have generallysquare-shaped lower portions each formed by yet another interconnectionof side edge portions of adjacent side walls;

FIG. 11 is a partial perspective of another exemplary embodiment of aframe of a shielding apparatus and illustrating a corner section of theframe that includes a lower portion formed by spaced-apart side edgeportions of adjacent side walls;

FIG. 12 is a perspective of another exemplary embodiment of a frame of ashielding apparatus;

FIG. 13 is a partial perspective of the frame shown in FIG. 12 andillustrating a corner section of the frame that includes a lower portionformed by spaced-apart side edge portions of adjacent side walls; and

FIG. 14 illustrates an exemplary method for making a shielding apparatusaccording to exemplary embodiments.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

As noted above, electronic circuits or components of a printed circuitboard (PCB) are often enclosed with shields to localize EMI within itssource, and to insulate other devices proximal to the EMI source. Oneknown way to form these shields is by stamping a piece of materialusing, for example, a die stamping process to form an enclosure, andthen folding side portions of the stamped piece of material downward,generally perpendicularly to form side walls. The shield may then beinstalled to the PCB to enclose the desired electronic circuits orcomponents. Structural integrity of such shields, however, tends to beimportant. Unfortunately, the folded side walls of the known die stampedshields may be susceptible to deformation before the shields have beeninstalled to PCBs. As recognized by the inventors hereof, shieldingapparatus (e.g., frames, shielding can, etc.) configured with partiallydrawn and partially formed corner sections may advantageously provideimproved structural integrity for resisting deformation. By way ofexample, the increased rigidity may thus provide a benefit prior toinstallation of the shielding apparatus to a PCB. During installation,flatness requirements can be especially important for ensuring propercontact to the solder paste thickness on the PCB prior to the solderingprocess. As disclosed herein, the inventors hereof have develops variousembodiments of parts with increased rigidity, which, in turn, may aid inmaintaining the flatness from the point of forming through installationat the point of use.

As disclosed herein, various aspects of the present disclosure relate toshielding apparatus that are suitable for use in providingelectromagnetic interference shielding for one or more electricalcomponents on a substrate. The shielding apparatus may have partiallydrawn and partially formed corner sections for improved rigidity. In oneexemplary embodiment, a shielding apparatus generally includes sidewalls configured to be disposed generally about one or more electricalcomponents on a substrate. Corner sections are integrally formed withthe side walls. Each corner section has a drawn portion integrallyconnecting a corresponding pair of side walls, and a lower portionlocated generally below the drawn portion and generally between sideedge portions of the corresponding pair of side walls.

In another exemplary embodiment, a shielding apparatus generallyincludes an upper surface and side walls integrally formed with anddownwardly depending from the upper surface. The side walls areconfigured to be disposed generally about one or more electricalcomponents on a substrate. The side walls have side edges that are eachconfigured for interlocking engagement with a side edge of acorresponding adjacent side wall. Corner sections are integrally formedwith the side walls and the upper surface. Each corner section includesa drawn portion integrally connecting a corresponding pair of side wallsand the upper surface. The drawn portion downwardly depends relative tothe upper surface. Each corner section also includes a lower portionlocated generally below the drawn portion. The lower portions includesseams formed by the interlocking engagement of the side edges of thecorresponding pair of side walls. For each corner section, there is alsoan opening located cooperatively defined by the drawn portion and thelower portion of the corner section.

Other aspects relate to methods of using and/or methods of makingelectromagnetic interference shielding apparatus having side walls and acorner section generally between each corresponding pair of side walls.In one exemplary embodiment, a method generally includes drawing a pieceof material to form a drawn portion for each corner section thatintegrally connects a corresponding pair of side walls. This particularmethod also includes forming the piece of material such that the sidewalls are configured to be disposed generally about one or moreelectrical components on a substrate, and such that each corner sectionincludes a lower portion located generally below the drawn portion andgenerally between side edge portions of the corresponding pair of sidewalls.

Referring now to the drawings, FIG. 1 is an exploded perspective of anexemplary embodiment of a shielding apparatus 100 embodying one or moreaspects. The shielding apparatus 100 is suitable for use in providingelectromagnetic interference (EMI) shielding to one or more electricalcomponents 101 on a printed circuit board 103 (a PCB, and more broadly,a substrate).

The illustrated shielding apparatus comprises a frame 102 and a lid (orcover) 104 that may be attached to the frame 102. In this particularembodiment, the frame 102 is advantageously formed by a combination offabricating processes including drawing the frame over a die, and thenfolding or bending part of the frame to produce the final desired shape.This method is described in more detail hereinafter. The finally shapedframe 102 is configured to be secured to the PCB 103 by means known inthe art. For example, the frame 102 may be secured to the PCB 103 bysoldering, mechanical fastening, etc. Together, the frame 102 and lid104 can enclose the desired electrical components 101 to provide EMIshielding thereto.

With reference to FIGS. 1 and 2, the illustrated frame 102 is generallyrectangular in shape and includes an upper surface 106 (or top surface),four side walls 108 formed integrally (or monolithically) with eachother and with the upper surface. The frame 102 also includes fourcorner sections 110 formed integrally with the side walls 108 and uppersurface 106. In other exemplary embodiments, at least part of the uppersurface 106 may be formed separately from the side walls 108 and cornersections 110 and be separately attached thereto. In still otherexemplary embodiments, the frame 102 may include more than or fewer thanfour side walls 108 and four corner sections 110, and/or side walls in aconfiguration different from that shown in the figures. For example, theside walls 108 may have a square configuration, a triangularconfiguration, a hexagonal configuration, another polygonal-shapedconfiguration, a circular configuration, a non-rectangularconfiguration, etc.

With continued reference to FIGS. 1 and 2, the frame's upper surface106, side walls 108, and corner sections 110 are formed from a singlepiece of electrically-conductive material so as to have an integral,monolithic construction.

A wide range of materials may be used for the frame 102. By way ofexample, the frame's upper surface 106, side walls 108, and cornersections 110 may be formed from cold rolled steel, nickel-silver alloys,copper-nickel alloys, stainless steel, tin-plated cold rolled steel,tin-plated copper alloys, carbon steel, brass, copper, aluminum,copper-beryllium alloys, phosphor bronze, steel, alloys thereof, or anyother suitable electrically-conductive and/or magnetic materials. In oneexemplary embodiment, the frame 102 is formed from a sheet of coldrolled steel having a thickness of about 0.20 millimeters. As anotherexample, the frame 102 may be configured from a suitable material havinga thickness in the range of about 0.10 millimeters and about 0.30millimeters. The materials and dimensions provided herein are forpurposes of illustration only, as the frame may be configured fromdifferent materials and/or with different dimensions depending, forexample, on the particular application, such as the electricalcomponents to be shielded, space considerations within the overallelectronic device, EMI shielding and heat dissipation needs, and otherfactors.

As previously stated, the frame's upper surface 106 is integrally formedwith each of the side walls 108 and corner sections 110. In theillustrated embodiment, the upper surface includes integral flanges 112that extend as one piece along each of the side walls 108 around theperimeter of the frame 102. Each flange 112 is bent inwardly along adraw line 114 with respect to each side wall 108 so that each flange 112is oriented generally perpendicularly relative to each side wall 108,with each side wall 108 depending generally downwardly from eachcorresponding flange 112. In other exemplary embodiments, the uppersurface 106 may include flanges 112 with openings therein, and/or mayinclude inwardly folded lips, perimeter rims, etc. In still otherexemplary embodiments, the upper surface 106 may include upper edges ofthe side walls 108.

The upper surface 106 also includes four cross braces 116interconnecting the flanges 112. The cross braces 116 extend from amiddle location of each of the flanges 112 to a central hub 118. Thebraces 116 are preferably configured to provide stiffening support tothe frame 102, for example, to resist deformation (e.g., bending, etc.).The cross braces 116 may also be configured to help maintain the sidewalls 108 in the generally rectangular shape of the frame 102. In otherexemplary embodiments, the cross braces 116 may extend from otherlocations of the flanges 112 (e.g., from corners of the flanges, etc.),and/or the cross braces 116 may extend directly to other locations ofthe flanges 112 without using a central hub 118. In still otherexemplary embodiments, the upper surface 106 may include no crossbraces. Or, the upper surface 106 may include more than or fewer thanfour cross braces 116 and/or in different orientations.

In the illustrated embodiment, the flanges 112 and cross braces 116define four openings 120 in the upper surface 106. These openings 120may be used, for example, to access the electrical components 101 of thePCB 103 contained within the frame 102 after the frame 102 is attachedto the PCB 103. In this embodiment (and embodiments in which the framedoes not include any cross-braces), the frame 102 may be viewed as anopen-top EMI shielding can. In other exemplary embodiments, there may bemore or less openings 120 in different sizes and/or shapes than what isillustrated in the figures.

Referring still to FIGS. 1 and 2, the side walls 108 of the frame 102are configured to generally surround certain electrical components 101on the PCB 103 when the frame 102 is attached to the PCB 103. As shown,each side wall 108 is substantially planar in shape. Adjacent side walls108 are oriented generally at right angles to each other, and opposingside walls 108 are generally parallel, thereby producing the generallyrectangular shape of the illustrated frame 102.

Each side wall 108 includes a lower edge portion 122 and a side edgeportion 124 extending upward from the lower edge portion 102. Each loweredge portion 122 is substantially co-planar with the lower edge portions122 of the other side walls 108. This co-planarity helps to provide agood mating surface with the PCB 103.

With reference now to FIG. 3, each lower edge portion 122 is also formedwith castellations 126 (e.g., formations with alternating notches 128and projections 130, etc.). The castellations 126 are preferablyconfigured to provide structure for connecting the frame 102 to the PCB103. For example, some exemplary embodiments have castellations 126 thatprovide areas for soldering the frame 102 to the PCB 103. In suchembodiments, the notches 128 allow solder to flow around the projections130 for securing the frame 102 to the PCB 103. In other embodiments, theprojections 130 of the castellations 126 may fit in correspondingopenings in the PCB 103 for securing the frame 102 to the PCB 103.Depending on the particular application, the castellations 126 may alsobe configured to allow for air flow to improve temperature uniformityduring the reflow process as well as for convection cooling duringdevice operation. The castellations 126 may also allow for fluid flow ifwashing processes are used on the completed PCB. In those installationsin which segmented solder traces are used that correspond with or matchthe castellations 126, the molten solder may also be confined to a localarea to thereby improve reflow process window. In still furtherembodiments, the frame 102 may not include any such castellations 126along its lower edge portions 122. In which cases, the frame 102 mayinclude generally straight lower edges portions 122. In addition,alternative means besides soldering may also be employed for securingthe frame 102 to the PCB 103.

As shown in FIG. 4, the side edge portion 124 of each side wall 108 isan edge that extends away from the lower edge portion 122 along eachside wall 108. In this particular embodiment, the side edge portions 124of adjacent side walls 108 are shown engaged at the corner sections 110along a seam 140. The side edge portions 124 of adjacent side walls 108are generally rounded and keyed in shape for interconnection. Forexample, the side edge portion 124 of one side wall 108 (e.g., the sidewall 108 to the left in FIG. 4) includes one finger or protrusion 132and two recesses 134. Correspondingly, the side edge portion 124 of anadjacent side wall 108 (e.g., the side wall 108 to the right in FIG. 4)includes two fingers or protrusions 132 and one recess 134. Accordingly,the fingers 132 of one side wall 108 are oriented to fit within thecorresponding recesses 134 of the adjacent side wall 108 to therebyprovide an interlocking engagement between the side edge portions 124 ofthe adjacent side walls 108. This interlocking engagement is preferablyconfigured so as to improve the rigidity or the frame 102, to helpensure proper alignment of the side walls 108 relative to one another,and to help ensure that the lower edge portions 122 of the side wallsare generally aligned and co-planar for providing a good mating surfacewith the PCB 103.

Referring now to FIG. 5, one of the frame's corner section 110 isillustrated generally from inside the frame 102. While only one cornersection 110 is shown in FIG. 5 and described hereinafter, the othercorner sections 110 of the frame 102 are substantially identical suchthat a description of the other corner sections 110 would essentially bethe same.

As shown in FIG. 5, the corner section 110 includes a drawn portion 136and a folded portion 138 formed by interconnection of the side edgeportions 124 of the adjacent side walls 108. In the illustratedembodiment, both the upper drawn portion 136 and the lower foldedportion 138 are generally rounded in shape.

The upper drawn portion 136 integrally connects the adjacent side walls108 and corresponding flange 112 of the frame 102. The upper drawnportion 136 is integral with the adjacent side walls 108 andcorresponding flange 112, such that the side walls 108 and upper drawnportion 136 depend generally downwardly relative to the flange 112.

The lower portion 138 is located generally below the upper drawn portion136. The lower portion 138 is defined by the interlocking side edgeportions 124 of the adjacent side walls 108 such that a seam 140 isformed thereby. An opening 142 is located between and cooperativelydefined by the upper drawn portion 136 and the lower portion 138 suchthat the opening 142 generally separates the upper and lower portions136 and 138 of the corner section 110.

In the illustrated embodiment, the seam 140 extends the length of thelower portion 138 of the corner section 110. In other exemplaryembodiments, the seam 140 may extend only part of the length of thelower portion 138. In still other exemplary embodiments, the opening 142may be located differently than illustrated in the figures. For example,alternative embodiments may not include any openings in the cornersection 110. In further embodiments, one or more openings 142 may beadditionally or alternatively located along the length of the lowerportion 138. For example, one of the side edge portions 124 may includea recess 134 to which the adjacent mating side edge portion does notinclude a finger 132 for fitting in the recess.

The upper drawn portions 136 of the corner sections 110 are preferablyconfigured to increase the rigidity of the frame 102. For example, theintegral construction of the upper drawn portions 136 with the adjacentside walls 108 and the corresponding flanges 112 at the corner sections110 preferably provides improved structural strength to the frame 102.This improved structural strength may help reduce undesired deformation(e.g., bending, etc.) as compared to other constructions (e.g.,constructions where the frame is formed by folding the side walls downdirectly from the flanges without any drawn portions, etc.).

Referring again to FIGS. 1 and 2, the illustrated frame 102 may beconfigured for handling by pick-and-place equipment (e.g., vacuumpick-and-place equipment, etc.). To this end, the central hub 118 may beconfigured (e.g., sized, shaped, etc.) for use as a frame pick-up areathat may be gripped or to which suction may be applied by thepick-and-place equipment for handling during, for example, fabricationof the frame 102 and/or installation of the frame to the PCB 103. Inother exemplary embodiments, the frame 102 may include, for example,tabs at the corners and/or along the side walls 108 as pick-up areas inaddition to or in place of the central hub 118.

FIG. 1 also illustrates an exemplary lid 104 of the shielding apparatus100. As shown, the lid 104 is configured (e.g., sized, shaped, etc.) tofit generally over the frame 102 for covering the openings 120 in theupper surface 106 thereof. At which point, the frame 102 and lid 104 maythus provide shielding to the one or more electrical components 101 onthe PCB 103 within the area cooperatively defined by the frame 102 andlid 104.

The lid 104 is shown with a generally rectangular shape corresponding tothe shape of the frame 102. The lid 104 includes sides 144 configured tofit generally over at least a portion of the side walls 108.Alternatively, the lid 104 may include more than or fewer than foursides 144 and/or may include sides in a configuration different fromthat shown in the figures. For example, the lid's sides may have asquare configuration, a triangular configuration, a hexagonalconfiguration, another polygonal-shaped configuration, a circularconfiguration, a non-rectangular configuration, etc.

In addition, the illustrated lid 104 includes a plurality of aperturesor holes 146. These holes 146 may facilitate solder reflow heatinginteriorly of the lid 104, may enable cooling of the electricalcomponents 101, and/or may permit visual inspection of portions of theelectrical components 101 beneath the lid 104. In some embodiments, theholes 146 are sufficiently small to inhibit passage of interferingEMI/RFI. The particular number, size, shape, orientation, etc. of theholes 146 may vary depending, for example, on the particular application(e.g., sensitivity of the electronics where more sensitive circuitry maynecessitate the use of smaller diameter holes, etc.). For example, someembodiments include a lid without any such holes.

In the illustrated embodiment, the lid 104 may be secured to the frame102 by soldering. In other exemplary embodiments, the lid 104 may bereleasably secured to the frame 102 in a manner that permits the lid tobe fairly easily removed and replaced onto the frame 102. For example,some embodiments include the frame's side walls being provided withprotuberances that are configured to align with and be retained bycorresponding openings formed in the sides of the lid. In otherembodiments, the frame's side walls may comprise one or more retainingopenings (e.g., recesses, voids, cavities, slots, grooves, holes,depressions, combinations thereof, etc.) configured to align with andengagingly receive one or more protuberances (e.g., catches, snaps,latches, tabs, detents, protuberances, protrusions, ribs, ridges,ramp-ups, darts, lances, dimples, half-dimples, combinations thereof,etc.) formed in the sides of the lid. In still other embodiments, theframe's side walls may include one or more retaining apertures and oneor more protuberances. Alternatively, other means can be employed forattaching the lid to the frame besides the engagement of protuberanceswithin openings.

The lid 104 may be formed from a wide range of materials, which arepreferably electrically-conductive materials. For example, the lid 104may be formed from cold rolled steel, nickel-silver alloys,copper-nickel alloys, stainless steel, tin-plated cold rolled steel,tin-plated copper alloys, carbon steel, brass, copper, aluminum,copper-beryllium alloys, phosphor bronze, steel, alloys thereof, or anyother suitable electrically-conductive and/or magnetic materials. In oneexemplary embodiment, the lid 104 is formed from a sheet of cold rolledsteel having a thickness of about 0.20 millimeters. As another example,the lid 102 may be configured from a suitable material having athickness in the range of about 0.10 millimeters and about 0.30millimeters. The materials and dimensions provided herein are forpurposes of illustration only, as the lid may be configured fromdifferent materials and/or with different dimensions depending, forexample, on the particular application, such as the electricalcomponents to be shielded, space considerations within the overallelectronic device, EMI shielding and heat dissipation needs, and otherfactors.

In other exemplary embodiments, the lid 104 may be formed integrally asa single component with the frame 102. For example, the upper surface106 may comprise a planar upper surface that extends substantiallyacross the frame 102 from one side wall 108 to another side wall 108,whereby the planar upper surface is integral with the corner sections110 and side walls 108. In such embodiments, the planar upper surfaceoperates as a cover or lid for the shielding apparatus 100. In whichcase, the shielding apparatus 100 is operable for shielding one or moreelectrical components 101 on the PCB 103 that are within an interiorcooperatively defined by the side walls 108, corner sections 110, planarupper surface, and at least a portion of the PCB 103. In someembodiments, the planer upper surface may include one or more throughholes or openings for ventilation, etc.

FIG. 6 illustrates a corner section 210 of a frame 202 of a shieldingapparatus according to another exemplary embodiment of the invention.While only one corner section 210 is illustrated in FIG. 6 and describedhereinafter, a description of the other corner sections 210 of the frame202 is the same. In this embodiment, the frame 202 includes side walls208 having side edge portions 224 formed with a different configurationof mating fingers 232 and recesses 234 for providing an interlockingengagement between the side edge portions 224 of adjacent side walls208. As shown in FIG. 6, in this embodiment the side edge portions 224of the adjacent side walls 208 each include one finger 232 and onerecess 234 oriented to interconnect.

FIGS. 7 and 8 illustrate a frame 302 according to still anotherexemplary embodiment. In this embodiment, the frame 302 includes sidewalls 308 having side edge portions 324. The side edge portions 324 areformed with a different configuration of mating fingers 332 and recesses334 for providing an interlocking engagement between the side edgeportions 324 of adjacent side walls 308.

As shown in FIG. 8, the interlocking side edge portions 324 engage toform generally square-shaped lower portions 338 of the corner sections310. The side edge portion 324 of one side wall 308 (e.g., the left sidewall 308 in FIG. 8) includes two fingers 332 and one recess 334, and theside edge portion 324 of an adjacent side wall 308 (e.g., the right sidewall 308 in FIG. 8) includes one finger 332 and two recesses 334. Thefingers 332 and recesses 334 of the side edge portions 324 of theadjacent side walls 308 are oriented to interconnect to form thegenerally square-shaped lower portions 338 of the corner sections 310.

FIG. 9 illustrates corner sections 410 of a frame 402 according to yetanother exemplary embodiment. While only two corner sections 410 areillustrated in FIG. 9 and described hereinafter, a description of theother corner sections 410 of the frame 402 would essentially be the sameand is therefore not provided. In this embodiment, the frame 402includes side walls 408 with side edge portions 424 formed with adifferent configuration of mating fingers 432 and recesses 434 forproviding an interlocking engagement between the side edge portions 424of adjacent side walls 408.

As shown in FIG. 9, the interlocking side edge portions 424 engage toform generally square-shaped lower portions 438 of the corner sections410. The side edge portions 424 of adjacent side walls 408 each includeone finger 432 and one recess 434. The finger 432 and recess 434 of theside edge portions 424 of the adjacent side walls 408 are oriented tointerconnect to form the generally square-shaped lower portions 438 ofthe corner sections 410.

FIG. 10 illustrates a frame 502 according to another exemplaryembodiment. In this embodiment, the frame 502 includes side walls 508with side edge portions 524 having no mating fingers or recesses.Instead, this embodiment has side edge portions 524 of the adjacent sidewalls 508 that abut each other below opening 542 to form generallysquare-shaped lower portions 538 of corner sections 510.

FIG. 11 illustrates a corner section 610 of a frame 602 according to yetanother exemplary embodiment. While only one corner section 610 isillustrated in FIG. 11 and described hereinafter, a description of theother corner sections 610 of the frame 602 is the same. In thisembodiment, the frame 602 includes side walls 608 with side edgeportions 624 having no mating fingers or recesses. Instead, the sideedge portions 624 of adjacent side walls 608 are separated by a spaceddistance or gap 650 generally below upper drawn portion 636 of thecorner section 610. In this embodiment, the lower portion 638 of thecorner section 610 is generally defined by the space 650 and thespaced-apart side edge portions 624 of adjacent side walls 608.

FIGS. 12 and 13 illustrate a frame 702 according to still anotherexemplary embodiment. In this embodiment, the frame 702 includes sidewalls 708 with side edge portions 724 having no mating fingers orrecesses. Instead, the side edge portions 724 of adjacent side walls 708are separated by spaces or gaps 750 below upper drawn portions 736 ofcorner sections 710. Thus, lower portions 738 of the corner sections 710are generally defined by the spaces 750 and the spaced-apart side edgeportions 724 of the adjacent side walls 708. As shown in FIG. 13, theupper drawn portion 736 of each corner section 710 extends downwardlyfrom an upper surface 706 of the frame 702 to a greater extent than doesthe drawn portions 636 of the frame 602 shown in FIG. 11. In FIG. 13,more of the frame's corner section 710 is formed by drawing than thatwhich is formed by bending or folding. The extent to which a cornersection of a frame, lid, shielding can, etc. is formed by drawing ascompared to folded or bending may vary depending, for example, on theparticular application.

FIG. 14 schematically illustrates an exemplary method 860 for making ashielding apparatus according to embodiments of the present disclosure.With this exemplary method 860, any of wide range of shielding apparatusmay be made, such as an EMI shielding apparatus (e.g., 100, etc.) havinga frame (e.g., 102, 202, 303, 402, 502, 602, 702, etc) and/or asingle-piece shielding can. As shown at process 862, a piece of material(e.g., a blank, etc.) is first stamped from a larger piece ofelectrically-conductive material(s) in the general form of, for example,a frame (e.g., 102, 202, 303, 402, 502, 602, 702, etc.). The form of theblank is generally flat and may include an upper surface (e.g., 106,206, 306, 406, 506, 606, 706, etc.) with flanges (e.g., 112, 212, 312,412, 512, 612, 712, etc.) integral with side walls (e.g., 108, 208, 308,408, 508, 608, 708, etc.) having side edge portions (e.g., 124, 224,324, 424, 524, 624, 724, etc.) and lower edge portions (e.g., 122, 222,322, 422, 522, 622, 722). In the blank, the side walls (e.g., 108, 208,308, 408, 508, 608, 708, etc.) radiate generally outwardly from theupper surface flanges (e.g., 112, 212, 312, 412, 512, 612, 712, etc.) sothat the side edge portions (e.g., 124, 224, 324, 424, 524, 624, 724,etc.) of adjacent side walls are spaced-apart. In some exemplaryembodiments, the blank may be formed from the larger piece of materialby a die stamping process. In other exemplary embodiments, the blank maybe formed from the larger piece of material by chemical milling, or byany other suitable process.

As indicated at process 864, the stamped blank is then formed. Duringthis forming process 864, the stamped blank is drawn or pulled over aforming die or punch. This forms corner sections (e.g., 110, 210, 310,410, 510, 610, 710, etc.) having drawn portions (e.g., 136, 236, 336,436, 536, 636, 736, etc.) integrally connecting corresponding flanges(e.g., 112, 212, 312, 412, 512, 612, 712, etc.) and adjacent side walls(e.g., 108, 208, 308, 408, 508, 608, 708, etc.). The drawn portions(e.g., 136, 236, 336, 436, 536, 636, 736) of the corner sections (e.g.,110, 210, 310, 410, 510, 610, 710, etc.) along with the integrallyconnected side walls (e.g., 108, 208, 308, 408, 508, 608, 708, etc.)depend generally downward from the flanges (e.g., 112, 212, 312, 412,512, 612, 712, etc.).

In addition to forming the drawn portions during process 864, the sidewalls are also formed during the same process 864. In other words, theside walls are formed along with the drawn portions during the sameprocess or operation 864 (and not in a separate distinct operationaccording to this exemplary embodiment). As the blank is being formedduring operation 864, the side walls are formed up to approximatelyninety degrees as the corners begin to draw over the forming punch.

As the drawing process continues at operation 864, the side edgeportions (e.g., 124, 224, 324, 424, etc.) of the adjacent side walls(e.g., 108, 208, 308, 408, etc.) are formed radially inward to meetalong the chosen interlocking geometry, if any. As disclosed herein, theinterlocking geometry may include mating or interconnecting fingers(e.g., 132, 232, 332, 432, etc.) and recesses (e.g., 134, 234, 334, 434,etc.) for providing an interlocking engagement between the side edgeportions of adjacent side walls. In other exemplary methods, the sideedge portions (e.g., 524, etc.) of the adjacent folded side walls (e.g.,608, etc.) may abut. In still other exemplary methods, the side edgeportions (e.g., 624, 724, etc.) of the adjacent folded side walls (e.g.,608, 708, etc.) may be spaced apart by a space or gap (e.g., 650, 750,etc.).

With further reference to FIG. 14, process 866 may include thefinally-formed frame (e.g., 102, 202, 303, 402, 502, 602, 702, etc)being be disposed generally about one or more electrical components(e.g., 101 in FIG. 1) on a PCB (e.g., 103 in FIG. 1) and installed(e.g., soldered, adhesively bonded, clipped onto, etc.) to the PCB. Alid (e.g., 104, etc.) may then be secured to the frame (e.g., 102, 202,302, 402, 502, 602, 702, etc), and together the frame and lid may beused to shield electrical components on the PCB inside and/or outsidethe frame from EMI.

It can be seen that the embodiments of shielding apparatus disclosedherein include corner sections (e.g., 110, 210, 310, 410, 510, 610, 710,etc.) that are formed partly by drawing a piece of material and partlyby folding, bending, or otherwise forming the piece of material. Thedrawing process 864 may advantageously provide improved strength to ashielding apparatus over those shields having side walls formed solelyby folding. As disclosed herein, shielding apparatus, frames (e.g., 102,202, 302, 402, 502, 602, 702, etc), and/or single-piece shielding cansmay include an integral, monolithic construction between side walls suchthat drawn portions of the corner sections (e.g., 110, integrallyconnect the adjacent side walls with the upper surfaces. This one-piececonstruction of the drawn portions, adjacent side walls, and uppersurfaces preferably provides improved strength and rigidity over atraditional folded construction. In addition, the process 864 duringwhich lower portions of the side walls (e.g., 108, 208, 308, 408, 508,608, 708, etc.) are folded or bent to a final form preferably eliminatesthe need for a draw flange along lower edge portions (e.g., 122, 222,322, 422, 522, 622, 722) of the side walls, which is typically common intraditional all-drawn constructions. This exemplary method alsopreferably eliminates the extra space typically needed on the PCB for anall-drawn construction. This, in turn, may help promote a more accurateand consistent fit of the lower edge portions (e.g., 122, 222, 322, 422,522, 622, 722) with a PCB (e.g., 103 in FIG. 1).

The materials and dimensions provided herein are for purposes ofillustration only, as the assembly and components thereof can beconfigured from different materials and/or with different dimensionsdepending, for example, on the particular application, such as thecomponent to be shielded, space considerations within the overallapparatus, EMI shielding and heat dissipation needs, and other factors.

The terms “integral” and “monolithic” are interchangeably used herein.Use of one term instead of the other term is not intended to belimiting. Both terms are intended to describe the one-piececonstructions disclosed herein for shielding apparatus, such as theframes 102, 202, 302, 402, 502, 602, 702, etc. As disclosed herein,various embodiments include a construction in which the upper surfaces(e.g., 106, 206, 306, 406, 506, 606, 706, etc.), side walls (e.g., 108,208, 308, 408, 508, 608, 708, etc.), and upper drawn portions (e.g.,136, 236, 336, 436, 536, 636, 736) of corner sections (e.g., 110, 210,310, 410, 510, 610, 710, etc.) are all formed as one piece. Thisone-piece construction is intended when using the terms “integral” and“monolithic” and variations thereof.

Certain terminology is used herein for purposes of reference only, andthus is not intended to be limiting. For example, terms such as “upper”,“lower”, “above”, “below”, “top”, and “bottom” refer to directions inthe drawings to which reference is made. Terms such as “front”, “back”,“rear”, “bottom” and “side”, describe the orientation of portions of thecomponent within a consistent but arbitrary frame of reference which ismade clear by reference to the text and the associated drawingsdescribing the component under discussion. Such terminology may includethe words specifically mentioned above, derivatives thereof, and wordsof similar import. Similarly, the terms “first”, “second” and other suchnumerical terms referring to structures do not imply a sequence or orderunless clearly indicated by the context.

When introducing elements or features and the exemplary embodiments, thearticles “a”, “an”, “the” and “said” are intended to mean that there areone or more of such elements or features. The terms “comprising”,“including” and “having” are intended to be inclusive and mean thatthere may be additional elements or features other than thosespecifically noted. It is further to be understood that the methodsteps, processes, and operations described herein are not to beconstrued as necessarily requiring their performance in the particularorder discussed or illustrated, unless specifically identified as anorder of performance. It is also to be understood that additional oralternative steps may be employed.

The description of the disclosure is merely exemplary in nature and,thus, variations that do not depart from the gist of the disclosure areintended to be within the scope of the disclosure. Such variations arenot to be regarded as a departure from the spirit and scope of thedisclosure.

1. A shielding apparatus suitable for use in providing electromagneticinterference shielding for one or more electrical components on asubstrate, the shielding apparatus comprising: side walls configured tobe disposed generally about one or more electrical components on asubstrate; corner sections integrally formed with the side walls, eachcorner section having: a drawn portion integrally connecting acorresponding pair of side walls; and a lower portion located generallybelow the drawn portion and generally between side edge portions of thecorresponding pair of side walls.
 2. The shielding apparatus of claim 1,further comprising a top surface integrally formed with the side wallsand drawn portions such that the side walls and drawn portions dependdownwardly relative to the top surface with each drawn portionintegrally connecting a corresponding pair of side walls and the topsurface.
 3. The shielding apparatus of claim 2, further comprising adraw line between each side wall and the top surface such that each sidewall is generally perpendicular to the top surface.
 4. The shieldingapparatus of claim 2, wherein the top surface defines an opening alongan upper portion of the shielding apparatus.
 5. The shielding apparatusof claim 4, further comprising a lid to cover the opening defined by thetop surface, whereby the shielding apparatus is operable for shieldingone or more electrical components on the substrate that are within aninterior cooperatively defined by the side walls, corner sections, topsurface, lid, and at least a portion of the substrate.
 6. The shieldingapparatus of claim 2, wherein the top surface, side walls, and cornersections are integrally formed from a single piece ofelectrically-conductive material so as to have a monolithicconstruction.
 7. The shielding apparatus of claim 2, wherein the topsurface is defined by the top edges of the side walls.
 8. The shieldingapparatus of claim 1, further comprising a top surface integrally formedwith the side walls and drawn portions such that the side walls anddrawn portions depend downwardly relative to the top surface with thedrawn portions integrally connecting the corresponding side walls andthe top surface, and wherein the top surface extends across theshielding apparatus from side wall to side wall, whereby the shieldingapparatus is operable for shielding one or more electrical components onthe substrate that are within an interior cooperatively defined by theside walls, corner sections, top surface, and at least a portion of thesubstrate.
 9. The shielding apparatus of claim 1, further comprisingflanges integrally formed with the side walls and drawn portions suchthat the side walls and drawn portions depend downwardly relative to theflanges with the drawn portions integrally connecting the correspondingside walls and flanges, and wherein the flanges extend inwardly relativeto the side walls so as to define an opening along an upper portion ofthe shielding apparatus.
 10. The shielding apparatus of claim 9, furthercomprising a lid to cover the opening, whereby the shielding apparatusis operable for shielding one or more electrical components on thesubstrate that are within an interior cooperatively defined by the sidewalls, corner sections, flanges, lid, and at least a portion of thesubstrate.
 11. The shielding apparatus of claim 9, wherein the flanges,side walls, and corner sections are integrally formed from a singlepiece of electrically-conductive material so as to have a monolithicconstruction.
 12. The shielding apparatus of claim 9, further comprisinga draw line between each side wall and the corresponding flange suchthat the side walls are generally perpendicular to the flanges.
 13. Theshielding apparatus of claim 1, wherein the side edge portions of theside walls are keyed for interconnection at the lower portions of thecorner sections for helping ensure proper alignment of the side wallsrelative to one another.
 14. The shielding apparatus of claim 1, whereinat least one of the side walls includes a lower edge portion withcastellations.
 15. The shielding apparatus of claim 1, wherein at leastone of the side walls includes a lower edge portion substantially freeof draw flanges and generally co-planar with the lower edge portions ofthe other side walls.
 16. The shielding apparatus of claim 1, whereinthe lower portions of the corner sections include seams formed by theside edge portions of the corresponding pair of side walls.
 17. Theshielding apparatus of claim 1, wherein at least one of the cornersections further includes an opening cooperatively defined by the drawnportion and lower portion of the corner section.
 18. The shieldingapparatus of claim 1, wherein the side edge portions of at least one ofthe corresponding pair of the side walls are separated by a spaceddistance at the lower portion of the corresponding corner section. 19.The shielding apparatus of claim 1, wherein the drawn portions of thecorner sections are configured to increase rigidity of the shieldingapparatus.
 20. A shielding apparatus suitable for use in providingelectromagnetic interference shielding for one or more electricalcomponents on a substrate, the shielding apparatus comprising: an uppersurface; side walls integrally formed with and downwardly depending fromthe upper surface, the side walls configured to be disposed generallyabout one or more electrical components on a substrate, the side wallshaving side edges each configured for interlocking engagement with aside edge of a corresponding adjacent side wall; corner sectionsintegrally formed with the side walls and the upper surface, each cornersection having: a drawn portion integrally connecting a correspondingpair of side walls and the upper surface, the drawn portion downwardlydepending relative to the upper surface; a lower portion locatedgenerally below the drawn portion, the lower portion including a seamformed by the interlocking engagement of the side edges of thecorresponding pair of side walls; and an opening cooperatively definedby the drawn portion and the lower portion of the corner section. 21.The shielding apparatus of claim 20, further comprising flanges definingthe upper surface and inwardly extending from the side walls so as todefine an opening therebetween, and wherein the shielding apparatusfurther comprises a lid to cover the opening, whereby the shieldingapparatus is operable for shielding one or more electrical components onthe substrate that are within an interior defined by the side walls,corner sections, upper surface, lid, and at least a portion of thesubstrate.
 22. The shielding apparatus of claim 20, wherein the uppersurface, side walls, and corner sections are integrally formed from asingle piece of electrically-conductive material so as to have amonolithic construction.
 23. The shielding apparatus of claim 20,wherein the side edges of the side walls are keyed for interconnectionat the lower portions of the corner sections for helping ensure properalignment of the side walls relative to one another.
 24. The shieldingapparatus of claim 20, further comprising a draw line between each sidewall and the upper surface such that each side wall is generallyperpendicular to the upper surface.
 25. The shielding apparatus of claim20, wherein at least one of the side walls includes a lower edge portionsubstantially free of draw flanges and generally co-planar with thelower edge portions of the other side walls.
 26. The shielding apparatusof claim 20, wherein the upper surface extends across the shieldingapparatus from side wall to side wall, whereby the shielding apparatusis operable for shielding one or more electrical components on thesubstrate that are within an interior cooperatively defined by the sidewalls, corner sections, upper surface, and at least a portion of thesubstrate.
 27. A method for making an electromagnetic interferenceshielding apparatus having an upper surface, side walls downwardlydepending from the upper surface, and corner sections generally betweeneach corresponding pair of side walls, the method comprising drawing apiece of material so as to form a drawn portion for each corner sectiondownwardly depending relative to the upper surface and integrallyconnecting a corresponding pair of side walls and the upper surface, andto form the side walls generally perpendicularly to the upper surfacesuch that each corner section includes a lower portion located generallybelow the drawn portion and generally between side edge portions of thecorresponding pair of side walls.
 28. The method of claim 27, whereindrawing further includes forming the side edge portions of the sidewalls inwardly to thereby interlock the side edge portions to eachother.
 29. The method of claim 28, wherein drawing includes bending orfolding the side walls.
 30. The method of claim 27, further comprisingforming the piece of material as a blank from a larger sheet ofelectrically-conductive material before drawing the piece of material.31. The method of claim 30, wherein forming the piece of material as ablank comprises at least one or more of stamping or chemically millingthe piece of material as the blank from the larger sheet ofelectrically-conductive material.